Author Topic: LIVE: Chang'e-2 (China's second lunar probe) - Long March 3C - October 1, 2010  (Read 192526 times)

Online Satori

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Solar panels have been open!

Offline HappyMartian

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Discussion on CCTV about Chang'e-2 data processing center and cooperation with EEU tracking and monitoring.

Cheers!
"The Moon is the most accessible destination for realizing commercial, exploration and scientific objectives beyond low Earth orbit." - LEAG

Online Satori

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Scientists and technicians are considering three possible extra missions for Chang'e-2, but no final plans were yet decided.

The first was staying in the lunar orbit, continuing to transfer data back to the earth for further research before eventually landing on the moon as an experiment for future lunar probes.

In the second scenario, Chang'e II would leave the Earth-Moon system, flying into outer space to test China's capability to probe further into space.

The third would be a "homecoming," altering its orbit to become an earth orbiter.

Offline JimO

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Scientists and technicians are considering three possible extra missions for Chang'e-2, but no final plans were yet decided.

The first was staying in the lunar orbit, continuing to transfer data back to the earth for further research before eventually landing on the moon as an experiment for future lunar probes.

In the second scenario, Chang'e II would leave the Earth-Moon system, flying into outer space to test China's capability to probe further into space.

The third would be a "homecoming," altering its orbit to become an earth orbiter.


I saw that news item too. The 'landing' could only be an impact mission, the probe has no terminal guidance system and I believe the thrusters aren't strong enough to hover even if it did. But it would be helpful for low-orbit navigation practice.

If there is enough excess delta-V to achieve earth-Moon escape (as Clementine did) that's good for the flag-waving but without a transmitter built powerful enough, and ground tracking dishes with enough sensitivity, it's hard for me to imagine how long they'd be able to keep contact, especially in the continuous full sunlight conditions (recall their anxiety about overheating when CE-1's orbit entered full sunlight briefly, on its mission?).

Offline HappyMartian

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Nice launch. Discussion on CCTV about Chang'e-2 instruments, low Lunar orbit of 100 km...

John S. Lewis, professor of planetary science at the University of Arizona’s Lunar and Planetary Laboratory has been the main CCTV foreign commentator prior to and during the launch and he is discussing Van Allen radiation belt and Solar radiation and Lunar chemical composition and the gamma ray spectometer and low orbit limitations.

Cheers!
"The Moon is the most accessible destination for realizing commercial, exploration and scientific objectives beyond low Earth orbit." - LEAG

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Scientists and technicians are considering three possible extra missions for Chang'e-2, but no final plans were yet decided.

The first was staying in the lunar orbit, continuing to transfer data back to the earth for further research before eventually landing on the moon as an experiment for future lunar probes.

In the second scenario, Chang'e II would leave the Earth-Moon system, flying into outer space to test China's capability to probe further into space.

The third would be a "homecoming," altering its orbit to become an earth orbiter.


I saw that news item too. The 'landing' could only be an impact mission, the probe has no terminal guidance system and I believe the thrusters aren't strong enough to hover even if it did. But it would be helpful for low-orbit navigation practice.

If there is enough excess delta-V to achieve earth-Moon escape (as Clementine did) that's good for the flag-waving but without a transmitter built powerful enough, and ground tracking dishes with enough sensitivity, it's hard for me to imagine how long they'd be able to keep contact, especially in the continuous full sunlight conditions (recall their anxiety about overheating when CE-1's orbit entered full sunlight briefly, on its mission?).

The earth-Moon escape scenario would be the more ambitious for China and could give them some experience in deep space tracking.

Offline JimO

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The earth-Moon escape scenario would be the more ambitious for China and could give them some experience in deep space tracking.

Compared to their scheduled Mars hitch-hiker mission? Several years ago, the practive would have been useful. Now it will conflict with the Mars mission requirements.

Online Satori

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The earth-Moon escape scenario would be the more ambitious for China and could give them some experience in deep space tracking.

Compared to their scheduled Mars hitch-hiker mission? Several years ago, the practive would have been useful. Now it will conflict with the Mars mission requirements.

Humm, well assuming Fobos-Grunt is launched on schedule ;)

The primary mission of Chang'e-2 ends around April 2011. Fobos-Grunt and YH-1 Yinghuo 1 are schedule for launch on November 2011.

If they send it to the deep space it will all depend on the amount of fuel left on the probe and the capacitu to maintain an operational status after so many months in space. A real challenge.

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An amazing photo collection of the launch of Chang'e-2 is available at http://www.chinanews.com.cn/tp/hd/2010/10-01/8032.shtml

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Another great photo collection is available at http://www.mod.gov.cn/photo/2010-10/01/content_4198124.htm

Online Satori

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The directional antena is now operational. The probe will send the first set of data tomorrow.

Offline spacex

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Congrats to China. Excited to see the mission results.

Offline Space Pete

Here's a video of the launch.

Electronic Engineer by day, NASASpaceflight's ISS Editor by night | Read my NASASpaceflight articles here

Online Phillip Clark

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After my post yesterday morning (UK time) I discovered that because of some quirk in this new-fangled Vista-thingey, some software that was giving perfectly good data under Windows XP is now churning out rubbish.

Oh well, I suppose it’s called “progress”.   I have now re-run the software on my XP machine and got some decent results!

At the time of the Chang'e 2 launch the lunar GHA was about 66 degrees and this, combined with a launch inclination of 28.5 degrees indicates a transit time between trans-lunar injection and lunar orbit injection of ~115 hours: this is more in line with the Chinese saying that the trip will take five days.

The transit time means that lunar orbit injection should come on October 6th at about 06:30 GMT, and at that time the lunar GHA will be around 300 degrees.   As a comparison, when the first lunar orbit injection burn for Chang’e 1 took place the lunar GHA was 288 degrees, so therefore the estimated time for the Chang’e 2 burn seems to be reasonable.

That’s what I like – consistent data!   The numbers never lie, but incompetent operating systems can make them appear to do so!
I've always been crazy but it's kept me from going insane - WJ.

Offline spacex

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After my post yesterday morning (UK time) I discovered that because of some quirk in this new-fangled Vista-thingey, some software that was giving perfectly good data under Windows XP is now churning out rubbish.

Oh well, I suppose it’s called “progress”.   I have now re-run the software on my XP machine and got some decent results!

At the time of the Chang'e 2 launch the lunar GHA was about 66 degrees and this, combined with a launch inclination of 28.5 degrees indicates a transit time between trans-lunar injection and lunar orbit injection of ~115 hours: this is more in line with the Chinese saying that the trip will take five days.

The transit time means that lunar orbit injection should come on October 6th at about 06:30 GMT, and at that time the lunar GHA will be around 300 degrees.   As a comparison, when the first lunar orbit injection burn for Chang’e 1 took place the lunar GHA was 288 degrees, so therefore the estimated time for the Chang’e 2 burn seems to be reasonable.

That’s what I like – consistent data!   The numbers never lie, but incompetent operating systems can make them appear to do so!


Phillip,
Xinhua reports "about 112 hours, or nearly five days" or a little less than what you have
http://news.xinhuanet.com/english2010/sci/2010-10/01/c_13539114.htm

Online Phillip Clark

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Thank you SpaceX for the 112 hours transit time - China announcing things takes the fun out of number-crunching!

I have been looking around for accurate times of Earth orbit injection (ie, time of the first third stage shutdown) and the start and end of the trans-lunar injection burn.   Has anyone seen these published anywhere, please?
I've always been crazy but it's kept me from going insane - WJ.

Offline HappyMartian

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Chang'e-2's launch was a great way to begin the Chinese National Day vacation. It will be interesting to see and read about the science that is produced.

Cheers!
"The Moon is the most accessible destination for realizing commercial, exploration and scientific objectives beyond low Earth orbit." - LEAG

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Offline Apollo-phill

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I wonder if we could encourage the Chinese to image the Apollo-15 site - which is roughly on 'opposite' side of Mare Imbrium to that of the Sinis Iridum (Iridium) (Bay of Rainbows ) - once their prime mission of hires imagery of the Sinus Iridum for Chang'e-3 is completed ?

I would expect quality to be same as LRO imagery of APollo-15 site ?



Offline input~2

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One of the engine from the CZ-3C first stage was recovered in Zhenyuan County, Guizhou province (SW of the announced Cengong drop zone).
Here is a picture showing time proven technology to haul the engine:

(more pictures here)
« Last Edit: 10/03/2010 01:31 PM by input~2 »